Many vehicle seat assemblies are known in which a backrest member of the assembly is hinged to a lower seat cushion for enabling the backrest to pivot forwardly or rearwardly with respect to the seat cushion. There are also a variety of inertia responsive latch mechanisms known to the art which lock the backrest against forward tilting movement in the event the vehicle experiences sudden deceleration, such as might occur during a panic stop or as a result of a frontal collision. One such latch mechanism is disclosed in U.S. Pat. No. 4,919,482 to Landis et al, granted Apr. 24, 1990 and assigned to the assignee of the present invention.
Rearward tilting of the backrest member is conventionally controlled by a reclining mechanism, of which there are many types known to the art. All known seat assemblies rely exclusively on the reclining mechanism to prevent undesirable rearward tilting of the backrest in the event the vehicle undergoes sudden acceleration, as might occur, for example, if involved in a rearend collision. Such reclining mechanisms, however, are prone to failure if subjected to extreme reclining forces.